Conventionally, in manufacturing of a rear axle, an axle end is shrink-fitted to an end portion of a rear axle housing connected to a differential. A brake flange inserted from the end portion of the axle end is shrink-fitted to the end portion of the rear axle housing, and the rear axle housing and the axle end are welded to the whole circumference of the circumference. Then, the rear axle housing and the brake flange are welded to the whole circumference of the circumference (for example, see Patent Literature 1).